acids, bases, and ph properties of acids 1. sour taste
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2. Contain hydrogen, react with active 2. Contain hydrogen, react with active metals to give off Hmetals to give off H22 gas gas
4. React with bases to produce salts 4. React with bases to produce salts and and
waterwater
e.g. e.g.
2NaOH + H2NaOH + H22SOSO44 → 2H → 2H22O + NaO + Na22SOSO44
Traditional definition of an Traditional definition of an acidacid
• A cmpd. That contains hydrogen and A cmpd. That contains hydrogen and ionizes in aqueous soln. to form ionizes in aqueous soln. to form hydrogen ions (Hhydrogen ions (H++))
Common acidsCommon acids
• HCl – hydrochloric acidHCl – hydrochloric acid
• HH22SOSO44 – sulfuric acid – sulfuric acid
• HCHC22HH33OO22 – acetic acid – acetic acid
• HNOHNO33 – nitric acid – nitric acid
• HH33POPO44 – phosphoric acid – phosphoric acid
Sulfuric acidSulfuric acid
• #1 industrial chemical#1 industrial chemical
• Fertilizers, petroleum refining, ……Fertilizers, petroleum refining, ……
• Used as a measure of a country’s Used as a measure of a country’s economyeconomy
Acid PrecipitationAcid Precipitation
• Combustion of fossil fuelsCombustion of fossil fuels– Is the main cause of acid precipitationIs the main cause of acid precipitation
2. Feel slippery to the skin2. Feel slippery to the skin
3. Change color of indicators3. Change color of indicators
4. React with acids to produce water 4. React with acids to produce water and saltsand salts
e.g.e.g.
2NaOH + H2NaOH + H22SOSO44 → 2H → 2H22O + NaO + Na22SOSO44
5. Bases are electrolytes5. Bases are electrolytes
Neutralization reactionsNeutralization reactions
• Reaction of hydronium ions (HReaction of hydronium ions (H33OO++) and ) and hydroxide (OHhydroxide (OH--) ions to form water) ions to form water
HH33OO++ + + OHOH- - 2H2H22OO
HCl + NaOH HCl + NaOH H H22O + NaClO + NaCl
(NaCl is a salt)(NaCl is a salt)
Sodium hydroxideSodium hydroxide
• ((NaNaOHOH), also known as ), also known as lyelye or or caustic caustic sodasoda, is a , is a causticcaustic metallic metallic basebase. It is . It is widely used in many industries, widely used in many industries, mostly as a strong mostly as a strong chemicalchemical basebase in in the manufacture of the manufacture of pulppulp and and paperpaper, , textilestextiles, , drinking waterdrinking water, , soapssoaps and and detergentsdetergents. Worldwide production in . Worldwide production in 1998 was around 45 million 1998 was around 45 million tonstons. .
If [HIf [H++] = 3.4 x 10] = 3.4 x 10-5-5 find pH find pH
= -[(log 3.4 + log 10= -[(log 3.4 + log 10-5-5)])]
= -[(0.53) + (-5)]= -[(0.53) + (-5)]
= -(0.53 – 5)= -(0.53 – 5)
= 4.47= 4.47
If the pH is 2 what is the If the pH is 2 what is the [H[H++]]
pH = -log [HpH = -log [H++]]
log [Hlog [H++] = -pH] = -pH
[H[H++] = antilog (-pH)] = antilog (-pH)
= antilog (-2)= antilog (-2)
= 1 x 10= 1 x 10-2 -2 MM
If the pH is 6.4 what is [HIf the pH is 6.4 what is [H++]]
[H[H++] = antilog (-pH)] = antilog (-pH)
= antilog (-6.4)= antilog (-6.4)
= 4.0 x 10= 4.0 x 10-7-7 MM
If the pH is 5.4 what is [HIf the pH is 5.4 what is [H++]]
[H+] = antilog (-pH)[H+] = antilog (-pH)
= antilog (-5.4)= antilog (-5.4)
= 4.0 x 10= 4.0 x 10-6-6 M M
[H[H++] [OH] [OH--] = 1 x 10] = 1 x 10-14-14
• Therefore if [OHTherefore if [OH--] = 1 x 10] = 1 x 10-10-10
pH = 4pH = 4
• if [OHif [OH--] = 1 x 10] = 1 x 10-7-7
pH = 7pH = 7
Diprotic acidDiprotic acid
• Can donate (2) protons (HCan donate (2) protons (H++) per ) per moleculemolecule
• e.g. He.g. H22SOSO44
Normality (Normality (N N ))
= (molarity) x (whole # factor)= (molarity) x (whole # factor)
# equivalents solute / L of solution# equivalents solute / L of solution
What is the normality of a soln w/ What is the normality of a soln w/ 1 mol H1 mol H22SOSO44 dissolved in 1 L of dissolved in 1 L of
soln?soln? 2 2 equivalentsequivalents x 1 x 1 molmol H H22SOSO44 = 2 = 2
equivalentsequivalents
1 1 molmol H H22SOSO4 4 1 1 L L 11 L L
= 2 = 2 NN H H22SOSO44
TitrationTitration
• Controlled addition & measurement Controlled addition & measurement of amt. of soln. of a of amt. of soln. of a knownknown conc. That conc. That is required to react completely with a is required to react completely with a measured amt. of soln. of measured amt. of soln. of unknownunknown conc.conc.
SaponificationSaponification
• hydrolysis of an ester under basic hydrolysis of an ester under basic conditions to form an alcohol and the conditions to form an alcohol and the salt of a carboxylic acid. salt of a carboxylic acid. Saponification is commonly used to Saponification is commonly used to refer to the reaction of a metallic refer to the reaction of a metallic alkali (base) with a fat or oil to form alkali (base) with a fat or oil to form soap. soap.